Three inter-related studies of oral cancer genetic epidemiology were conducted in Taiwan during the past year. These studies were aimed at determining the basic causes of this disease. First, we have studied a case-control sample and found an association between genetic variation at the Cytochrome P450 gene 1A1 which interacts with exposure to risk factors such as smoking and drinking. Second, we have obtained questionnaire data regarding the family history of this disease and correlation with risk factors. Third, we have identified 100 families suitable for sampling for gene mapping studies based on linkage and/or linkage disequilibrium approaches and this sampling of blood, oral rinse, tumor tissues and questionnaire data has commenced.